Wednesday, October 9, 2013

According to EC2 pricing for on-demand instances in a multi-tenant mode and in dedicatedmode there is an apparent slight difference of $0.006 on instance per hour fee, plus $2 per hour per region when one instance at least is activated on a dedicated mode.

So, using AWS Simple Monthly calculator I have searched how pricing evolves depending on the number of instances you are running in dedicated mode.

First of all, if you run only 1 dedicated "small" instance, 100% of the time, it will cost you ... $1512 a month! $782 per instance, if you run 2 dedicated instances, and so on. Here is the complete comparison matrix:

Observe that running 10 instances in dedicated mode is still 343% more expensive than running these instances in a multi-tenant mode.

This pricing model starts to be "attractive" for significant number of instances (>500) or for instances with a low rate of utilisation.